Magneto



Aug. 4, 1925.

E. URBAIN ET AL MAGNETO Filed July 25, 1921 Patented vAug. 4, `1925. UNITED- STATES" e 1,548,226 PATENT OFFICE.

EDOUARD URBAIN AN D CLAIR SCAI', 0F PARIS, FRANCE. i

MAGNETO.

Apnation mea .my l,25, 1921. smal Naasaus.

(GRANTED UNDER THE rnovrsroNs 0F Tun AcT or Manon a, 1921, 41 STAT. L., 131s.)

To all whom t may concern.'

Be it known that we, EDOUARD URBAIN and CLAIR ScAL, citizens of the Republic of France, and residing at 30 Avenue de lObservatoire, Paris, France, and 49 Rue Vaneau,

Paris, France, have invented certain new and useful Improvements in or Relating to Magnetos, for which we have been granted` a patent in France No; 517,413, Dec. 17, 1920, of which the following is a specification, reference being had therein to the accompanying drawing.

Ignition devices for explosion engines comprise a so-called low tension magneto discharging into condensers, which condensers afterwards discharge into the primary of an induction apparatus, and in the secondary of which is obtained the high tension necessary for the sparking plugs.

In an apparatus of small power and volume, the advantages of the-great simplicity` of this system are odset by a serious drawback, in that there is delay in the charging of' the condensers, and this delay increases with the speed.

The delay is allY the more .pronounced since, instead of using a strictly sinusoidal form of wave, it is sought to approximate it tov the shape of a rectangle, in order to obtain quicker flux variations, and consequently higher potentials for the low speeds.

. The harmonics are not shifted in the sameI way at the different speeds, and the intensity curves corresponding to the different speeds, are very dissimilar.

vrl`his invention has for its objects to eliminate the injurious eects of theAsaid delays, and to give a lixed advance to the ignition,

acharged.

4.-Discharging the condenser at the end of a certain time into the primary of the induction apparatus.

5.-Suppressing the breaking of the ar mature-condenser circuit on a certain speed Vbeing' reached, which makes it l ssible to give an advance to the ignition 1f the discharge of the condenser into the primary of the induction apparatus of the stage 4 showing different positionsl of the switch which is intended in one position to give a fixed advance to the ignition at high speeds and in another position to cut out the ignition.

The disc l, that is madeof a'good conduc'- tive material, comprises four sectors, of which two (3, 3) are of good conductivity, being constituted, for instance, by two s mmetrical parts of the disc, and the two others (2, 2) are insulating parts, being constituted, for instance, by recesses of the disc. Said disc is rigidly mounted on lthe shaft of the magneto, from which latter it is electrically insulated; it turns at the same speed as vthe said shaft of the magneto.

The armature of the magneto may be mounted on they axle, as in the largest number of magnetos, or it may be stationary as in the magnetos *with rotatable magnets. One of the poles of the armature is earthed andthe other pole is connected directly, or 'through a brush, to the disc 1.

ln the drawings the magneto is shown very -diagrammatically 7 is the armature, of

whichthe pole 8 is connected to the disc 1,

and the other pole 9 is earthed..

Two shoes 4 and 5 are placed so as to press on the full parts 3, 3 of the disc 1, and so as not to fall in the recesses 2, 2 of said'disc, thisresult being obtained by limiting the displacement of said shoes or by filling up the recesses 2, 2 with some insulating material. f

The shoe 4 is earthed orrconnected to the mass of the magneto, as at 10, while the shoe 5, that is insulated fromthe mass, yis connected to the pole 11 of the condenser, the other pole 12 being earthed, or connected respond to the differentVv phases of the Working of the magneto are as follows:

1. When the disc 1 is in one of the positions shown in Figs. 1 and 4, the shoe 4 presses against one of the sectors 3 and the armature of the magneto is short-c1rcu1ted, the pole 8 being earthed through l and 4.

2. When the disc 1 is in the position shown in Fig. 2, the shoe 4 has just abandoned one of the sectors 3 and is in front of one of the in contact with the other sector 3; a breaking takes place and the induction current at breaking charges upy the condenser through the shoe 5.

3.- Wlien the disc is in the position shown in Fig. 3, the shoe 5, in its turn, abandons lthe corresponding sector 3, and the condenser, being insulated, remains charged.

4. Vhen the disc is in the position shown in Fig. 4, the two shoes 4 and 5 are in contact with the conductive parts of 'disc 1. The shoe 4 has been first attained by one of the sectors 3 and the armature of the magneto has been again short-cireuited.

Then theA shoe 5 comes in contact with the other sector 3, and the pole 11' of the condenser is then earthed or connected to the mass through 5, 1 and 4.

The discharging of the condenser takes place suddenly, through the intermediary of the primary 13 of the transformer on the one hand, and through. 5, 1 and 4 o`n the other hand. This sudden discharge produces in the secondary 14 of the transformer the current giving the ignition spark.

By the choice of the relative dimensions of the sectors 3 and of the relative dimensions and positions-of rthe shoes 4 and 5, it is possible to retard broadly this latter contact and to produce the spark with a retardation greater than the retardation due even at high speeds to the phenomenon ofself induction in the armature.

5. At high speeds, the shoe 5 is placed out of circuit (Fig. 5) by directly connecting the pole ll of the condenser to the pole T8 of the armature; a fixed advance to ignition is thus obtained if an arrangement has been made so that the mechanical retardation at small speeds should be greater than the functional electric retardation which alone comes into action at high speeds.

This result is obtained through the use of. the switch 6 that is placed in the position'shown in Fig. 45, wherein 11 is connected to 8 through disc l.

. Fig. 6 shows switch 6 in a position shortcircuiting the armature and thus cutting out the ignition.

One of the chief advantages of this device consists in the fact that if accidentally after parts 2, the other shoe 5 being a condenser and` primary switch mechanism operating with the armaterminah connecting said movable bosses acting in the desired Se-- quence.

The switching out of the brushes insulated` from the mass by the continuous electric connection of the' condeiisers to the disc, may also be eii'ected outside the magneto, at any desired distance and if desired this may be rendered automatic. i

It must be. clearly understood that the mechanical and electric construction hereinbeforedescribed in detail -is not intended in any way to restrict the generality of the principles hereinbefore set forth, or to limit the scope of the invention.

What we claim is:

l. In an ignition system for internalcombustion engines, a primary circuit including a generator, a condenser and primary coil, and switch mechanism operating in synchronism with said generator and, suc cessively, short-circuiting the armature of said generator, closing the primary circuit through said armature, breaking said shortcircuit, opening the-primary circuit, and finally closing the primary circuit exclusive of said armature.

2. Inan ignition system for internal combustion engines, a primary circuit including c'oil, a magneto,

ture of said magneto and periodically per- Vforming the following functions in succession short ciicuiting said armature, closing the primary circuit through said armature,

roo

opening -said short circuit, opening the primaryy clrcuit, closing the `primary circuit exclusive of said armature.` i 3. In an ignition system for internal combustion engines, a partial circuitincluding a condenser and a'primary coil, a generator, a first terminal connected to one side of said partial circuit, a second terminal connected to the other side of said partial circuit andto one pole of said generator, and switch mechanism operating in synchronism with said generator and periodically performing the following functions in succession: connecting saidecond terminal with the other pole of said armature, connecting said first terminal with said other pole, disconnecting said second terminal, disconnecting said first terminals. 4. In an ignition system for internal combustion engines, a partial circuit including a condenser and primary coil, a generator, a first terminal connected to one side of said partial circuit, a second terminal connected to the other side of said partial circuit and to one p ole of said generator, switch mechanism rotating with said armature and performing the following functions in succession: connecting said second terminal with the other pole of said armature, connecting said first terminal with said other pole, disconnecting said second terminal, disconnecting said first terminal, connecting said .terminals; and a manually operated switch adapted to cut out said first terminal and connect said other pole of the armature to the first-mentioned side of said partial circuit.

5. In an ignition system for internal combustion engines, a partial circuit including a condenser and primary coil, a. generator, a conductive disc rotating in synchronism with said generator and electrically connected to one pole of the armature thereof, a first brush contacting said disk and electrically connected to one side of said partial circuit, a second brush contacting said disc on the opposite side of the axis of rotation thereof from said first brush and connected to the other side of said partial circuit and to the other pole of said armature, opposite portions of said disc adapted to break electrical Contact with said brushes and said brushes being so arranged that said second brush makes electrical contact with said disc slightly in advance of said first brush.

6. In an ignition system for internal com- .bustion engines, a partial circuit including a condenser and primary coil, a magneto, a

conductive-disc rotating with the armature4 of said magneto and electrically connected to one pole of said armature, a first brush contacting said disc and electrically connected to one side of said partial circuit, a second brush contacting said disc on the opposite side of the axis of rotation thereof from said first brush and connected to the other side of said partial circuit and to the other pole of said armature, opposite portions of said disc adapted to break electrical contact with said brushes and said brushes being so arranged that said second brush makes electrical contact with said disc in advance of said first brush, and a switch adapted to close a connection between said disc and said first brush.

l7. In an ignition system for internal combustion engines, a partial circuit including a condenser and a primary coil, a magneto, a conductive disc rotating with the armature. of said magneto and electrically connected to one pole of said armature, a first brush contacting said disc and electrically connected to one side of said partial circuit, a second brush contacting said disc on the opposite side of the axis of rotation thereof from bustion engines, a primary circuit including a condenser and primary coil, a magneto, and switch mechanism rotating with the armature of said magneto and, successively, short-circuiting the said armature, closing the primary circuit through said armature, breaking said short circuit, opening the primary circuit, and finally closing the primary circuit exclusive of said armature.

Intestimony whereof we hereunto afiix our signatures.

EDOUARD URBAIN. CLAIR SCAL.

Witness- .JEAN LAFOREST. 

